Accurate fault location algorithms for two parallel transmission line using one-end data

A novel numerical algorithm of fault location estimation for an inter-circuit four line fault with ground connection is presented in this paper. This is based on one-terminal voltage and current data. The loop and nodal equations comparing the faulted phases to nonfaulted phases of two-parallel circuits are introduced in the fault location estimation models, in which source impedance of the remote end is not involved. The effect of load flow and fault resistance on the accuracy of fault location are effectively eliminated, therefore a precise algorithm is derived. The algorithm is demonstrated by digital computer simulations